Signal-to-Noise Ratio of Intraoperative Tibial Nerve Somatosensory-Evoked Potentials

Abstract

To reveal the intrinsic signal-to-noise ratio (SNR) of single-trial somatosensory-evoked potentials (SEP). SEP was recorded from 13 scoliosis patients during surgery. The power of SEP was estimated with least-square fitting to obtain the most accurate value and then to estimate the SNR of every trial of SEP. The SNR of cortical SEP from 13 cases presented individual difference among each other. According to the mean and standard deviation, the coefficients of variation of cortical and subcortical SEP were 4.2% and 23%, respectively. The SNR of SEP was estimated to be -24 +/- 1 dB in cortical SEP and -22 +/- 5 dB in subcortical SEP. The lowest SNR of individual case was found to be -30 dB in cortical SEP and -53 dB in subcortical SEP. The results showed that SNR of intraoperative SEP recordings varies from person to person and presents a higher variability in subcortical than that in cortical, with a broad range from -53 to -5 dB. The results from this study can be used to understand the nature of SEP signals, which could guide researchers and designers on SEP denoising method selection, extraction, and measurement, as well as equipment development.

Time jitter of somatosensory evoked potentials in recovery from hypoxic–ischemic brain injury

“…SSEPs are only several microvolts in amplitude (Meissner et al, 2004) and are always accompanied by different kinds of noise, including biological noise from the subject and electrical noise from instrumentation and surrounding environment (Hu et al, 2010). The signal to noise ratio (SNR) of SSEP is especially low during the first two hours post-CA.…”

Preliminary studies of neurosensory and cardiopulmonary health compromise in captive– bred Rhesus macaques (Macaca mulatta) suffering scoliosis

“…On the other hand, several studies have described the SEPs diagnostic value as a non-invasive neurological tool for the evaluation of somatosensory pathways commonly used during the trans-operatory period in the surgical correction of IS [5,8,20,34,35]. It is worth mentioning that our literature review failed to provide information regarding dysfunctions of the electrical conductivity in the peripheral and central somatosensory pathways related to scoliosis in rhesus monkeys; nevertheless, baseline data regarding electrical conductivity of somatosensory pathways in Rhesus macaques has been recently documented in captivebred monkeys [17].…”

Single-trial detection for intraoperative somatosensory evoked potentials monitoring

“…Continuous SEP data were band-pass filtered between 20 and 2000 Hz (Cruccu et al 2008;Hu et al 2010b). SEP epochs were then extracted using a window analysis time of 100 ms (0-100 ms post-stimulus).…”

“…However, the magnitude of SEPs (about 1-2 lV) (Nuwer et al 1999;Cruccu et al 2008) is several times smaller than the magnitude of the background electroencephalography (EEG) activity, thus resulting in a low signal-to-noise ratio (SNR) of SEPs in single trials Hu et al 2010b). In order to enhance the SNR and identify the SEP responses, ensemble averaging is the most widely used approach in the time domain (Dawson 1951(Dawson , 1954.…”